Are aphids, whiteflies and mealybugs picnicking in your summer garden?

Q: Aphids are taking over my new okra plants, and I have mealybugs and whiteflies everywhere on shrubs. Help!

A: Whiteflies, aphids and mealybugs — summer’s Triple Crown! Warm weather invites them to come out of hiding to spread their blankets for picnics in your summer garden. They likely did not just travel there for vacation. They set up housekeeping last year, hiding out to wait for picnic season, when they explode on the scene in their bikinis, beach blankets in hand, ready to party. Control began last winter while we were snoozing by the fire.

These pests are related — cousins in the Hemiptera family — and, like annoying cousins at the reunion, share annoying family traits. All three pierce plant tissue to suck juices, often spreading diseases as they slurp. All three produce a sticky residue called “honeydew,” a medium for the growth of black sooty mold, which is not a disease but is only there because the plant is hosting the Hemiptera family. All three reproduce fast and furiously, especially in summer.

Maybe it’s the heat. Or the bikinis. Most aphids are actually born pregnant. Figure that one out.

You have characterized your problem as pests “taking over … everywhere” so you don’t just have a few bugs that natural predators will control — you have an infestation (think the beach at Spring Break).

You need Integrated Pest Management for a healthier garden, but right now you need a quick takedown so IPM can be developed. Use a summer oil to quickly reduce mealybugs and whiteflies on shrubs.

Aphids are fairly localized, lazy and sedentary, so you can control them by zapping plants daily with a strong water spray to knock them off. Dislocated aphids usually stay dislocated. You can also consider starting new okra transplants in fresh, healthy soil, tending them well so they produce in the shortest possible time (55 days), and using IPM methods to give you okra as long as the weather remains warm enough, even if you’ve lost this crop to the Hemiptera cousins.

The first week of July is not too late here to plant okra. Finally, you can spray this infested crop with malathion. This time of year, watch for fire ants, stinkbugs and leaf-footed bugs on okra, too. Fire ants love okra and will damage it. Use ant bait on the perimeter of the garden area.

Keep the plant watered, using drip or soaker hose methods. As with all chemicals, follow label directions explicitly, since product safety and effectiveness are tested and assured only by those directions.

IPM recognizes that instead of “nuking” our garden we need to maintain and protect the ecosystem balance in our yard in the way that is safe and most likely to be effective in the long term. Use a combination of techniques: crop rotation, mulch, compost, mechanical control (hand picking bugs or using traps), biological controls (Bacillus thuringiensis, beneficial bugs like ladybugs and parasitic wasps, planting trap plants to draw bugs away), improved cultural practices and, as a last resort, minimal low-impact chemical application.

Use dormant-season oil for a variety of pests in winter when most beneficials are elsewhere. Remember, what kills the bug also kills the predator killing the bug, creating a Circle of Death instead of the Circle of Life your garden needs. The malathion on the okra kills the aphids but also kills any ladybug it hits, and one ladybug can eat 60 aphids a day.

Some IPM controls for aphids on okra include: 1) anchor aluminum foil to the soil for 1 foot around new transplants to repel aphids; replace foil when no longer reflective; 2) use traps: paint a shallow pan bright yellow, fill with soapy water; place several in the garden; paint 6-inch x 8-inch squares bright “safety” yellow, coat with a thin layer of Tack Trap and attach to stakes set among plants; 3) mix 2 tablespoons of hot red pepper, 2 garlic cloves, 1 tablespoon of liquid soap and 1 quart of water; spray plants, reaching undersides of leaves; 4) spray plants with insecticidal soap which kills on contact, having no residual activity.

About The Author

Mobile County Master Gardeners are volunteers dedicated to improving quality of life by sharing horticultural knowledge & facilitating community projects. The Alabama Master Gardener Volunteer Program is an educational outreach program provided and administered by the Alabama Cooperative Extension System.